#include <iostream>

using namespace std;

int main(void) {
  int n,m,nr,nc,r[100],c[100],i,j;

  cin >> nr >> nc >> n >> m;
  if (!cin)
    return 1;

  // nr and nc between 1 and 10000
  if (nr < 1 || nr > 10000)
    return 1;
  if (nc < 1 || nc > 10000)
    return 2;

  // n + m <= 100, n and m each >= 0
  if (n < 0)
    return 3;
  if (m < 0)
    return 4;
  if (n + m > 100)
    return 5;

  for (i=0;i<n+m;i++) {
    cin >> r[i] >> c[i];
    if (!cin)
      return 6;

    // r,c between 0 and n{r,c}-1
    if (r[i] < 0 || r[i] >= nr)
      return 7;
    if (c[i] < 0 || c[i] >= nc)
      return 8;
    // r,c unique
    for (j=0;j<i;j++)
      if (r[i] == r[j] && c[i] == c[j])
        return 9;
  }

  // we win!
  return 42;
}